1. Field of the Invention
The invention relates to a method for the tool-free production of bodies, especially hollow bodies, from vitreous silica, in which vitreous silica threads and/or vitreous silica wool are bonded permanently together. It furthermore concerns the use of the bodies made by the method.
2. Discussion of Prior Art
It is known from German Pat. No. 682,606 to produce objects of vitreous silica by pressing vitreous silica wool into molds and melting it. It is furthermore known to produce comparatively large boards from vitreous silica wool. For this purpose the vitreous silica wool is carried by means of a conveyor belt and a roller through a large chamber in which the individual glass threads are welded together. Bodies of vitreous silica have also been made by uniting vitreous silica threads under heat and pressure. Furthermore, it is known to produce thin, flexible bands and sheets of any desired width from fused vitreous silica by shaping a felt-like mass of threads or staple fibers into a thin band or a thin sheet, and then weld together the individual fibers of the band or sheet under pressure and appropriate heat.
German Pat. No. 1,127,040 teaches the production of opaque bodies from parallelly arranged mineral threads. The threads drawn from dies are welded side by side immediately after emerging from the dies, at a temperature of 500.degree. to 800.degree. C., and under pressure, and then immediately cooled.
The production without tools of articles of glass or minieral fibers is known from German Auslegeschrift No. 1,200,725. In this case, first a mat is formed from a fiber mixture, and is then heated rapidly from the ambient temperature to about 600.degree. C., the mat being then subjected to a slight air pressure without the use of mechanical pressing or shaping elements.